Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the tool is known to be a safe read operation. The description goes beyond annotations by explaining the special mapping for UK (ISO code accepted, jurisdiction_label carries UK), how machine fields carry ISO codes, and that the result includes EU member and state/provincial/cantonal overlay. This adds valuable behavioral context without contradicting any annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, information-dense sentence that packs all essential details: purpose, examples, jurisdiction list, UK special case, and output components. No filler or redundancy; every clause earns its place. It is front-loaded with the action and examples, making it easy for an agent to grasp the tool's function quickly.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given that an output schema exists, the description does not need to explain return values in detail, but it still hints at the output structure (machine fields, jurisdiction_label, EU member, overlays). It covers the input format and special cases, leaving nothing critical unknown for correct invocation. The only minor omission is error handling for invalid ship_to values, but that is not essential for a read-only, idempotent tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0% (no parameter description), so the description carries the full burden for explaining the ship_to parameter. It provides concrete examples (US-CA, CA-ON, MX, EU-DE, UK, etc.), clarifies that ISO 3166-1 codes are accepted, and details the output fields. This fully compensates for the minimal schema and gives the agent a clear understanding of valid input formats.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb (resolve) and resource (ship-to to jurisdiction), enumerates the exact jurisdiction set (US · CA · MX · EU · UK · KR · JP · SG · CH) and includes concrete input examples. It is unambiguous and clearly distinguishes from sibling tools like resolve_actor, which deals with actor resolution rather than geographic jurisdiction.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description clearly implies the use case: when you have a ship-to identifier and need to know the gate's jurisdiction, EU membership, and regional overlays. However, it does not explicitly mention when not to use it or name alternatives (e.g., resolve_actor). The context is clear enough that an agent would correctly infer when to call it, but explicit exclusions are absent.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.